body {
  margin: 0;
  padding: 0;
  font-family: -apple-system, "Microsoft YaHei UI", BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Oxygen',
'Ubuntu', 'Cantarell', 'Fira Sans', 'Droid Sans', 'Helvetica Neue',
  sans-serif;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}
:root {
  font-size: 15px;
}
code {
  font-family: source-code-pro, Menlo, Monaco, Consolas, 'Courier New',
  monospace;
}

* {
  box-sizing: border-box;
  //transition: all 0.7s;
}

::-webkit-scrollbar  {
  width: 6px;
  height: 6px;

}
::-webkit-scrollbar-track  {
  background-color: #ddd;
}
::-webkit-scrollbar-thumb  {
  background-color: #555;
}